Elayne's Descent

As an additional cost to cast this spell, exile a
creature named #1 - Elayne, Lady Mage
you control.
Create a 15/15 Whale creature token with
flying and trample and "When this creature
attacks or blocks, sacrifice it at the end of
combat. When this creature dies, return an
exiled card named Elayne, Lady Mage to the
battlefield tapped under its owner's control."